typedef int data_t;

typedef struct{

    data_t *data;
    int maxlen;
    int top;
}sqnode, *sqstack ;

sqstack stack_create( int len ); //创建栈
int stack_push( sqstack s, data_t value ); //进栈
int stack_empty( sqstack s ); //判断栈是否为空
int stack_full( sqstack s ); //判断栈是否满了
data_t stack_pop( sqstack s ); //出栈
data_t stack_top( sqstack s ); //栈顶元素
int stack_clear( sqstack s ); //清栈
int stack_free( sqstack s ); //回收栈
